"We are announcing today that after a great deal of thought and discussion, we have decided to separate ... This is very much a mutual and mutually supportive decision that we have made together following a process of long and careful consideration. We ask for respect for our privacy and that of our family, and we do not intend to comment further."

Back in the 1990s, I spent a lot of time interviewing people about relationships, dating and sex. So I must say I don't find this particularly shocking in the scheme of modern life.

We are now living longer and having fuller lives than any time in history. This is especially true for women, who are no longer financially dependent on their husbands.

As for marriage itself, it was never designed to make it through life spans that now tilt into the 80s and 90s. Childhood sweethearts hitting their 60s now find another lifetime spreading out before them. It makes you think, but also wonder what else you have to discover with one another.

The modern era brings many challenges, relationships suffering the most. It must also be said that just because you stay together doesn't mean a marriage has worked better. Sometimes religion forms the bond that cannot be broken, even if the marriage has long ago ceased to mean what marriage is to mean.

In other cases, two people just reach the end of the road on which they began. There is no more mystery or sensual chemistry, a friendship blooming in place of romance. This is great if you're 80; not so exciting if you're healthy and only in your 60s.

Life expectancy can throw 'til death do us part into a tailspin, to which the famous are not immune.